In general, a gas carburizing process would require an atmospheric heat treating furnace herein called heat treating furnace along with a gas generator for conventional carburizing. However there are existing designs that use heat treating furnaces for carburizing without a gas generator. Example of this is a drip feed type furnace with Methanol for direct carburizing.
Prior art and problem to be solved: In the conventional method, the carburization starts from the time heat treating furnace attains the temperature of 930° C. to begin the process, but in the present invention the carburization starts from 800° C., 850° C., 900° C. to 930° C. In the conventional method the process of quenching takes place with low agitation quenching & oil velocity (rpm), wherein in the present invention the agitation varies from 1200-1500 rpm with high velocity rate of quenching.
This cooling apparatus of the present invention is a significant innovative step as compared to conventional cooling apparatus.
The present invention reduces the total cycle time during carburization and diffusion in the carburizing process, and to lower the production cost of the carburization processing. The present invention allows carburization on a part to start from 800° C. by adding LPG or propane along with methanol during heating and during the withholding duration. The other object of the invention is to begin carburizing much earlier than what it would have achieved after beginning of carburizing at 930° C.
Further object of the invention is after the process of completing carburizing process; the parts need to be quenched. The Quenching apparatus in this invention has made significant changes as compared to conventional quenching apparatus which is about 0.25 in−1. The further object of the invention is to enhance the severity of quench apparatus by surpassing the conventional severity of quench by 0.43-0.8 in−1.